Background and objective: Paradoxical vocal fold motion dysfunction (PVFMD) is a disorder of the larynx characterized by adduction of the vocal cords during the respiratory cycle leading to symptoms of extrathoracic airway obstruction. PVFMD mimics asthma and patients with PVFMD (PVFMD+) are often diagnosed incorrectly as refractory asthma and receive unnecessary treatment. This study determined the prevalence of PVFMD in asthma patients and described the relationship between asthma and PVFMD.
Methods: A descriptive study of 94 asthmatic patients and 40 control subjects, all of whom were examined via laryngoscopy and had pulmonary function tests were performed.
Results: The prevalence of PVFMD was 19% (n = 18) in the asthmatic group and 5% (n = 2) in the control group (P < 0.001). No relationship was found between presence of PVFMD, asthma attacks and asthma severity (P > 0.05). Laryngopharyngeal reflux and allergy were significantly more prevalent in the PVFMD+ group than in the group without PVFMD (PVFMD-) (P < 0.05). The most common symptoms in the PVFMD+ patients were difficulty in breathing (88%), inspiratory stridor (66%) and a choking sensation (50%) and the most common symptoms in PVFMD- asthmatic patients were cough (63%), dyspnoea (55%) and wheezing (51%).
Conclusions: Asthma seems to facilitate the formation of the paradoxical dysfunction in the larynx as the prevalence of PVFMD in asthma patients is significantly higher than in patients with out asthma.